Extraction and Cleanup of Organochlorine and Organophosphorus Pesticide Residues in Fats by Supercritical Fluid Techniques

Abstract

A supercritical fluid extraction and cleanup procedure was developed for separating organochlorine and organophosphorus pesticides from fats. Supercritical carbon dioxide modified with 3% (v/v) acetonitrile was used to extract the pesticides at 6O°C and separate the pesticides from the fats at 4000 psi and 95°C on an in-line C? silica-based column. The extraction and cleanup procedure gave good recoveries for 43 of 62 nonpolar to moderately polar organochlorine and organophosphorus pesticides from fats, whereas 49 were recovered through conventional Florisil column cleanup before quantitation. This procedure can extract and clean up pesticide residues from 0.65 g animalbased fat and 1.0 g oils. Coeluted residues in the pesticide fraction ranged from 2.5 mg for butterfat to 0.8 mg for corn oil. Results for samples analyzed with this integrated extraction cleanup procedure were reproducible and comparable with results obtained with the current Total Diet Study methodology.

Supercritical fluid extraction of pesticides from meat: a systematic approach for optimisation

“…SFE was performed using a 7680T Hewlett-Packard (Waldbronn, Germany). In the optimised method samples were extracted in a randomised sequence with pure CO 2 at a flow rate of 2 ml min 21 for 2 h at 0.40 g ml 21 and 95 °C. Extracted compounds were collected on a Florisil trap at 35 °C.…”

“…The column was a DB1701 (J&W Scientific, Folsom, CA, USA) capillary coated with a phenyl-cyanopropyl-methyl phase (30 m 3 0.32 mm id, 0.5 mm od, 0.25 mm film thickness). Helium (1 ml min 21 on column) was used as carrier gas. Detection was by NPD using hydrogen as make up gas and a temperature set point of 250 °C.…”

“…Detection was by NPD using hydrogen as make up gas and a temperature set point of 250 °C. The temperature programme was: 1 min at 70 °C followed successively by a 30 °C min 21 increase to 180 °C and 4 °C min 21 to 260 °C maintaining this final temperature for 20 min. Total GC analysis time was 45 min.…”

“…28 In a recent work Hopper has been able to extract organochlorine and organophosphorus pesticides from fats using SFE. 21 Evaluating numerous pesticides and food matrices SFE was found to be comparable to the traditional method used in the United States Department of Agriculture (USDA) Total Diet Study. Still, Florisil clean-up of SFE extracts was required and as presented the methodology cannot readily be totally automated.…”

“…SFE has been employed for extraction of pesticides and chlorinated compounds such as PCBs from fatty matrices. 2,6,21 Characteristically, the end determination is made by GC with ECD or NPD, and clean-up of extracts is often required. Clean-up is typically performed off-line whereby the potential for automation is reduced.…”